The present invention relates to powder-actuated tools and, more particularly, to a pole extension device for use with such tools.
The use of extension devices, to enable the discharge of powder-actuated tools at a point remote from the user, is well known. The most common such application being in placement of fasteners in ceilings or other overhead locations beyond the unassisted reach of the tool operator. Through utilization of an extension device, the need for ladders or scaffolding may be avoided and the speed and ease of fastener installation may be increased.
The most common of the presently employed types of pole extenson devices comprises a pole, means of attaching the tool to one end of the pole, and a lanyard looped over, or otherwise engaging, the tool trigger. Such devices, although simple and effective, suffer in that the act of pulling the lanyard tends to affect the tool alignment at the moment of firing, resulting in misaligned placement of the fastener. The alignment problem is aggravated by the presence of a safety interlock (now mandatory) in the tool firing system, which requires that the tool muzzle be pressed against the workpiece while the tool is being discharged. The operator is thus required to push upward on the pole while pulling downward on the lanyard and, at the same time, maintaining proper tool alignment.
It is, therefore, an object of the present invention to provide a simple and reliable pole extension device, adapted for use with a powder-actuated tool, allowing discharge of the tool without imposition of a biasing or misaligning force thereon. This is accomplished, in general, by the provision of a twistable handle, telescopingly carried on an end of a hollow pole or body and adapted to effect discharge of the tool consequent to rotation relative thereto. More specifically, an inelastic cable, disposed within the body, is engaged at one end thereof with the tool firing mechanism and attached at the other end to a pin riding on a cam mounted for co-rotation with the handle, whereby rotation of the handle draws the cable away from the tool, discharging the same.